In a brake device, braking force is generated by the pressing together of a rotating member which rotates together with an output shaft, and a fixed member which is fixed to the vehicle body side, and friction generates heat in the rotating member. A lubrication device therefore cools the rotating member by feeding lubricant between the rotating member and the fixed member, and keeps the temperature of the rotating member from increasing.
Even if the brake device is in a released state in which the rotating member and the fixed member are not pressed together, in a case in which a large amount of lubricant is present between the rotating member and the fixed member, A loss of driving force may occur due to a portion of the driving force of the output shaft being transmitted from the rotating member to the lubricant.
In order to prevent such a loss of driving force, in the technique described in Japanese Unexamined Patent Application Publication No. 53-034054, a lubricant circuit is provided for increasing the supply amount of lubricant in a case in which the brake device is in the braking state, and reducing the supply amount in a case in which the brake device is in the released state.
Japanese Examined Patent Application Publication No. 6-3228 discloses a technique for reducing the amount of oil after a momentary time delay, rather than reducing the amount of lubricant at the same time that the clutch is released.